Drop pit apparatus



Sept. 22, 1953 Filed Jan. 14. 1950 L. D. HOLMES ET AL DROP PIT APPARATUS5 Sheets-Sheet l INVENTOR. LOUIS DHolmes &

Roberf 8. Hammond W7 ATTORNEY Sept. 22, 1953 Filed Jan. 14, 1950 l D.HOLMES ET AL,

DROP PIT APPARATUS 5 Sheets-Sheet 2 INVENTOR. Louis D. Holmes &

Ro'ber! $.H0mmond Sept. 22, 1953 Filed Jan. 14, 1950 l... D. HOLMES ETAL DROP PIT APPARATUS 5 Sheets-Sheet 3 INVENTOR.

Louis D. Holmes 81 Robert S. Hammond ATTORNEY P W I Sept. 22, 1953 D.HOLMES ET AL 2,652,784

DROP PIT APPARATUS Filed Jan. 14, 1950 5 Sheets-Sheet 4 JNVENTOR. LouisD. Holmes a BY Robert 8. Hammond F 8 ATTORNEY I 23w il 5 Sept. 22, 1953Filed Jan. 14, 1950 5 Sheets-Sheet 5 H 1| W" "m l I "In W l 43 13 24 T'1' ll "W I! W L DJI'Y'VEINTOR. a ouls mes F l G- 7 BY Robert 5. HammondATTOR N Y Patented Sept. 22, 1953 "I TED S E NT iiO FiFlC E "DROP PITAPPARATUS 1Lom's D.-.Ho1mes;"B1ue IslandgeandsltohertSrHammolidi'winnetka; 111.; assignors to Whiting Cor- ?poration; a;-corporation of Illinois Application-January 14, 1950;"Serial No.138;!378

9;.Glm'ms.

-;Qnr inventiomisflireeted to pimp. :table: appa-,.'ratus,r.partioularlyzof thetype employed inapit extendingtransverselyvbeneathla series. ofc-r'alilroad tracks and utilized'f'orraising ancl' -lowering tops which bridge the pit.

ZDrop xtableiinstallationsx areuwid'ely employed :in; rai1road::shopswherecit is frequently necesrsary:to-exchanige'trueks, axleassemb1ies,-or= the :like railway 'svehioles. .tThese installationsusually include: onewor more. service traokaexi-tendinglaterallyavzithrespect to a transverse pit and1bridged.zbya'suitable.service tra'clrfltops: re- :rleasably anchored'ittos'the--pit walls. Ininstances of: .this' type; arzdrop table is mountedfor movementupon-:railsextending longitudinally along tthapit'bottomandissprovidedwith a lifting platf'iOEIXlIJIIIOVZtblB upwardly intoengagement with 'nthevvarions'stopsispanningtherpit. When a:vehieleistto;beservricemeas:by removaliofsa truck,

ritzisrmovedialonga the servieetrackrails until the tnunkito;be::removedx:is-; disposedxon the service rtraokutop. The :dropztableapparatus is then :usuallyi;bronghtiintoxeposition belowzthe ztop; the

topudisengagedzl romzthe pit'awalls, and the top and vehicleraised-slightly byi therdrop table; apz.-.paratus,- =whioh permitsengagement :of .the body of the vehiclezby suitable:body:supportsfdisposed ::near thertop. The table: .andztop-rarel: then10W- :eredgso thatthe truck orwwheelwassembly can-be ridisengagedsandesubsequentlyeloweredawhile. in :po'sitionaonthe top into the pit bythEldI'Op table. :The. tables. is'zthenemoved laterally along: the: pitaan'dysubsequeri tlytelevatednuntilta the rails .on'. the atop tarealignment/with: the: rails of; a suitable release track or storage piton to which the wheels C01. tru'cksiare to be discharged. r si-m ilarusage is :made 50f the ;.apparatus. 01,10,ther.2punp0seS, S1ICh:iasrrepa-inon replacement ofzspringsaoroither run- .nning*g'earlassociated; .With the; vehicle.

5 considerable'lperiodrof time.

A third expedient sometimes employediistto "hinge therelease track' topat one end soethat its oppos'lte-endemay be:raisedewithssuitahlemoisving equipment. Whi le zt'hisipermits: elevation of 0 ma servicetra'okltoprto theialevetofithe' releaseltraek rails, travel is:blo'okedzvmznne'rdireetion onzthe release track and.alltmaterial"fonmerlyirdisposed aoniithe: release traemtopmustnbetremoved sp rior ntoura-ising! the top. lFztil-urez-ofiropesandzlhoisting 1 equipment: makes such anwoperation.hazardous to the workmen anot'inaddition.consumeseappreoiable time.

"In other installations, four'heavy rposts are I manually plaoeclsuitableso'ckets idisposedzon I the liftingplatform or thee-r01 table?impo "to engage' the'prider side of the rel-ease'etraoktop.

the platform is 'raised: 'earrying with it the service track top; therelease 'traek-top iscarried v upwardly on the osts-thuspermittingthe1service'track'top-to reach release traeklevel. 'I'I hese "posts-must,i'-however,i be remove'clfi from the drop table before the releasetrack top ean loe lowered F below release traelc level -or before theclrop table --*oarilbe movecld'ongitudinally aiong'rlthespit. flit isL10 th'erefore: necessary to repeatthe operation frequently. lSeveral-workmen areof 'course required =to perform this: operation,Whieh *eonsumesi considerable time and ispeooming increasingly moredihloult -as' the size and weight of table tops ing5 crease.F'urthermore; the posts, =whioh are usually' earried- -on the-"droptable-apparatus may interfere with *the *movement' of --tru'oks= or=axle assemblies on to and off of the table.

'Gne-Of 'the 'most important objects of our iniiihelpasty; cmlsidelalbley s been to vention is to overcome"the above-men'tiond andother'disadvantages-'ofprior art devices through the provision of a.drop" table installation Which Will automatically elevate 1 a "releasetraek top when the lifting* platform of 'the cl-rop table is raised from'below the release'traok top.

Another primary objeot of our invention is e to provide a drop tableinstallation in -xv-hich the upward movement of the lifti-ng platform ofa -droptable beneath the release track topyiill-"elevate the toponlywhena' service track topisucan- -=ried on the lifting platform.

Otherimportant objects inblu'de the provision -'of a drop tableapparatus-which requires'only a relatively shallow pit,whiizh-mayabe'operated :by

i thepit by an overhead crane; thuspermitting single workman-locatedeitherat arr-emote point or at the table, and which inherently preventsthe unintentional nesting of tops upon the lifting platform of the droptable.

Further objects of our invention, as well as the details of constructionor our preferred embodiment and its many advantages, will be disclosedin the following description of our invention and the appended drawings,in which;

Fig. l is a diagrammatic plan view of a typical drop table installation;

Fig. 2 is a diagrammatic elevation of the arrangement shown in Fig. 1;

Fig. 3 is a diagrammatic partial elevation of a drop table in positionbelow a release track p;

Fig. 4 is a partial diagrammatic elevation of a drop table operatingwithout a top on a lifting platform;

Fig. 5 is a partial cross section through one of our vertical posts;

Fig. 6 is a partial diagrammatic elevation of our device in operationwith a top in position on a lifting platform;

Fig. 7 is a partial diagrammatic elevation showing our apparatus asillustrated in Fig. 6 in a partially raised position; and

Fig. 8 is a partial diagrammatic elevation illustrating the position ofour device with a release track top in position on the lifting platform.

Briefly, we accomplish the objects of our invention by providing fourupright posts mounted for vertical reciprocation in the pit walls belowthe release track top. Means are provided for connecting the releasetrack top to the posts, either permanently or releasably as required bycircumstances. Our drop table includes a lifting platform carrying fourlaterally projecting stirrups spaced apart a distance equal to thespacing of the posts, whereby the stirrups can be aligned by movement ofthe drop. table with laterally projecting lugs secured to the lowerportions of the posts. Thus the drop table may be racked into positionbelow the release track top and as the platform is raised the stirrupswill engage the lugs on the posts, thus causing the posts to moveupwardly carrying the release track top.

In some installations, particularly where remote control is to beemployed, we provide means for preventing accidental nesting of therelease track top on a service track top. This apparatus includes alever arrangement carried by the platform and including an arm whichactuates a lower limit switch, the latter being utilized to limit thedownward movement of the lifting platform. If a service track top is inposition on the lifting platform, the lever mechanism is actuated toraise the switch-engaging arm of the mechanism, thus permitting theplatform to travel downwardly a greater distance than would be permittedif the lever were in unactuated position. When the lifting platform ispermitted to fall to this position, the stirrups will be at a levelbelow the lugs on the posts, whereby upward movement of the platformwill elevate both the posts and the release track top. If, however, theservice track top is not in position on the lifting platform, theswitch-actuating arm of the lever system will be in a depressed positionand therefore actuate the low level limit switch to stop the platform atan intermediate position wherein the stirrups on the lifting platformare above the level of the lugs on the posts. Elevation of the platformunder such conditions will not actuate the posts and will permit thelifting platform to engage the release tracl; top, which may thereafterbe lowered on the platform.

Automatic operation from a remote point is attained by suitablypositioning limit switches which fix the position of the drop table onthe track, and which limit upward and downward movement of the droptable lifting platform. When thus installed it is not necessary toassign one or more workmen to duty in the thus effecting a substantialsaving in labor. In addition, speed of operation is substantiallyincreased over that possible by manual operation, and the number ofmistakes occurring is substantially reduced, since improper operation ismade virtually impossible.

In Figs. 1 and 2 we have illustrated a typical drop table installation,wherein a plurality of service tracks in extend over a drop table pit H,the gap being bridged by service track tops l2 releasably held inposition by engagement with the pit wall. Pit I extends transverselybeneath the level of the tracks it and includes longitudinal walls i3normally of concrete. P ils it extend along the bottom of the pit i lcarry a drop table, generally designated 95. Preferably, body sup-portmembers II are mounted at floor level near the service tracks ill andare utilized to support the body of a railway vehicle while the trucksor axle assemblies are being lowered on one of the service tracks top12. A release track !8 also extends across the pit H, being bridged by arelease track top l9. Frequently a tunnel 2i is formed below the releasetrack and opens into the pit ii, serving as storage for re conditionedtruck and axle assemblies.

The drop table It is basically conventional in design and includes aframe 22 to which rail wheels 23 are journaled. The frame 22 alsocarries four upwardly extending screw members 24 suitably interconnectedby gears, and driven by a reversible motor 25 for raising and lowering alifting platform 2?, which engages the threads on the screws 24. Thelifting platform 2! usually consists of beams 28 secured together toform a square or rectangular outline, and of such length and width toreceive and support the release track top l9, and the service track topsI 2.

The service track tops l2 are usually of greater depth than the releasetrack top is. For convenience we therefore provide legs 29 extendingdownwardly from the bottom of the release track in registry with thebeams 28 a distance sufiicient to make the overall depth of the releasetrack [9 equal to the overall depth of the service track tops l2.

In the longitudinal walls [3 of the pit H, immediately below the releasetrack I3, we provide four channel-shaped, upwardly extending members SI,in which we mount a plurality of rollers 32 carried by opposed shafts 33secured to the members 3!. Posts 34, preferably in the form of H orI-beams, are fitted within the channelshaped member in such manner as tobe supported for sliding vertical movement by the rollers 32 and byengagement with the inner walls of the member 3 i. If desired, bearingblocks 3% may be secured to one or more of the faces of the posts 34 forengagement with the members 3i. One of the surfaces of the posts 34 isapproximately flush with the surface of the longitudinal walls l3.

Lugs 31 are fixed to the lower portions of the posts 34 and projectoutwardly into the pit at a predetermined level above the rails 14. Lips3e are formed on the upper portions of the posts 34 for engagement withretractable bars 4| reeciproca-lly mounted zontthei release trackztop l9i"be*TpBITmll'/lid tQil-QWEI ;or'rlyitoitsaintermedi'ate and actuated byrods 42. Stirrups 4:3;areerfixed epos'ition .in;which..the;level;of:therstirrups: 43* is 3110 the 'ilirtingtplatformsz'lofithetdropa-table l6 :la' bovextherlevelsofilihe lugs;l3l., .UpvvardmovesarrdtrpnojecuJateraillyzbeyond:therliftingw platform ment of thelifting platform beneath ztherelease :towardsthellcingitudinalawva'llst3tof2the5pitg5be- 5 itraclntop 29:;maythereforebeaccomplishedwithling:spacedrsapartva xdistancecequal to. the longiout-movement of. thepostsand the lifting platitirdinalLdistancerbetweentthezzposts :34 ;lin;such"form broughtf intoengagement withathe :release:manner:lthatttheyzzmayirbe-vertically alignedifor top 59.iUnintentional nesting of xthe :release .zeirgagem'ent :with .the lugs13-! \bylimovementj of tUaCki'llOp OnL the service "track: top .155thus- Y-ren- Ether dropl'table lSi-alongtth tracks M. 'tdered virtually:impossible, and r the: necessity of ThEidEOPi table 2 i6 .is :providedwithsan supper mai u y nl cin r vy POStSlin position t e :limitswitchiddzirrthepatheofithelifting platform :zliiting platformis-eliminated. ;:2.1';-for;:1imiting upward;'fmovementandga lower Aspreviously indicated, i, there are: manyiin- 11 13; t m jh lattgrbeing;.disp0sed;;ln..l3h stallationswvhere nit-is :ldesired to alsoraisethe .pathztofztancarmz41;:of anb'ell crank lever'5.0;piv- 15 traektopiNYWIIBII :p iof the ojyaflyr mqunted ggn theflifting platform 21, A :CiIQp table ii isuactuatedfrom position beneath vweightzfizi ay :beesecure'drto .the arm z41,:the thereleasettrack'top, regardless ofwhetherzor gmovement; fi i hyi jlitflitedflbyjstops 49, The 15131011thererisraservice track top imposition on the :zotherzarmM-S :ofthecbell crankzEOrnormally prop m il. iUnder such circum'stancesaitlisob- :jeets laterally.upwardlyiabove;the uppensurface 2 *Vi0us'that.the "bell; crank: leverfEO may :be .elimif t JQ f th p1gtform; 2'l;landis deiznatedmndentheccorrventionalistopmemberrpro-@pressed-;byfingagementwithVa stop g -.-v-. t ,vided for actuationiofthe low level. limit-switch 'itop:;-isi-irL-. osi'tion on.the .rplatform21. =Wherr so 516. The;stopr:m.ember will:.0f course beadjustedcdepressed the endriof thesarm-ufltisvraised,lthus 130181101?dOll/nWardiImm/ementthe platform??? pemittingthe platform- 2"- t tdownwardly -:and at-apointwherethelevel' of thestirrupsllliizlaetgreaterizdistanoebefore the end: of the'arm 4'! the platform 27 sbe10w=:the.ievel ofithelu s t t v g lm t t -.45 w in this; J31 ontheposts-3'2. It is also possible. under such asitinmutheslevelaofzllthe-stirnups43 carried-by the m ncesto; pe m n ly securethezrelease .aliiting platfonmrzlrzisibelow'the-levelror the lugs ekposts, althou h this is seldom desirable. 5:3"! :onithapostsrfll;ewithrthe result that the drop 3,0 -n mplianee with R. S. 4888,werhave ide- -1 ;p1 t get engage t u --not"\v-ish to limit ourselvesspecifically totthe, form maaiwith m q aj ca usingvthe t gq to =hereindescr1bed-except in so far as definedtitby upwardly. Since thereleasettrack top lflris-supappel'ldedi Claims- :rportedtbyzthecpostsi3tlathruughr'the bars 4|, it fl :lma'yibe'seenithattherreleasetrack topwill :be car- 1 "Apparatus i017use"il'l'connefitioniwithla pilfid'lllpwa'llfilyilby? thei posts; permittingrthetservi :pltwf: t havg .an-eloneatedpit extending ceitrackztopt2-. to:ber-raised toitheslevel.of the 40=-- r n verse1y ':beneath a plurality of railway r lea tra'klig, itraeksz land v bridg d by a servicev track atop andWhenthereisrno service traekl'top onltheslift- 'fl'eleaselmck 0Dvertica'lly for-use' in :matform Hit-the weightymjforces the-arm,vservioing railway avehicle trucks and. the like 'iupwardlyihuslowering.thezfreaendrof thearm i p sl' ig a drop table having'a-framemovable it. When: irr*such-:position,;the limitzswitch 46ng-rails:.onathe:bottomofxxthe'p tmafi fi willtbes-actuatd: to .=stop:.the lifting. platform;- 2'! oplfli'iform iilhe me, power means on thezatsana'intermediatei level somewhat-above'the low fi engaging gj'p torm forrdriving i -level previously! described; thelifting plat- 'ldownbetween a111711131391" :form filmisiinits.intermediatecposition;ltheustir- 1911 a d a-l0wer position, uprightp t d srrupsi43oaretdisposedeatadevelabove the level. of 50 1 in p frelease' tracki'top ztherlugsiltl. L'IlhfliidIGPjlifliblBf l6.maytherefore andzengageab th t lifting Ithe p, :betmovedjnto position:below .therelease track G l Y-Suppo ting the posts for ii-too" i 9;-

platform Z'Irraisdewithoutmoxreiinovement'llpivlafdly and d wnwardly,anclyspaced iml'lll bf ullhe116517534. xTheslegssZflEon the-:release-QPl r d thfl liftingvplatform 't gk enggg ithegplatform521 bhupgrmitting ;:and projecting laterally therefrom towardsrthe *1 therelease: track: top i he toi-"beedis n a 1 \postsl forengagementtherewith as the lifting tthe posts;il lnloyactuationcofithe;loekingzbars 'fl raisedirom lower p ition--136-loweredzmththe;'liftingrplatform. 'Theiarm at ck pwgzthowever,'willnotr-bezaotuated; sincethasposts Apparaws e v C ctwn W th adrop29;i1o1d the:body ofitheirelease track-top, i9.v in cot-t f a tim v n ane dp extending 3113elevatedfposifiOn"WhBre: it can"nottengage;theLtransverselyebeneath a plurality of railway tracks and bridged byaservioe track top and release iarm w.

{Fl-011113113 foregoing it may 1 t h tracktop'inovable' vertically foruse in servicing s-everaa serviceztraek topz'isrcarried by the'tliiftingw y v trucks and l p i n a :platform, the..arm- Mewill -be -:actuated:inw such-'-65"drop"tab=le'having'a frame m bl along-r3115 rmannerast0.:-permit theL-lifting platform to. drop "'OIT'lihG"bOlltOlllOf' thepit, a liftingplatform on ;taritsrlowest'position. When :irr thisposition the the"'frame,-power means on th frame engagingdevel.OfHtheTstirrupsH-M is; below; .-the;=1evel of the the' tingplatformfor driving the platform up alugslil'l: on the :posts34,-- Withtheresultthatany and dowribetweenan upper position andaiower upwardmovement of the lifting platform z 2'li7o 'xpo'sition, upright :po'stsdisposed in the pit be- --when:-itisr-below: the 'release track top l9 Wfifiiillfiherelfiasetrack p de eageable there- -zcausethe-posts:-34--and the release tra'ekltop l9 "W lihIiOl; lifting:thetop,11rneans for" r i u ?=to:. ber1ifited with 1 the liftingplatform. v'If,f=.in saupporting thezposts, an inward iplojecting 1:uether iwords lthe lifting platform 21 :doesanotxecl,Ltoqthexlower-portion: ofieach of the posts 1 earryla:servicetrackrtop, the liftingvplatformmilli 7521811016 a: plura y u w yp s cti e I stirrups fixed to the lifting platform and disposed thereonfor registry beneath said lugs when the lifting platform is in its lowerposition below the release track top.

3. Apparatus for use in connection with a drop pit of the type having anelongated pit extending transversely beneath a plurality of railwaytracks and bridged by a service track top and a release track topmovable vertically for use in servicing railway vehicle trucks and thelike comprising a drop table having a frame movable along rails on thebottom of the pit, a lifting platform on the frame, power means on theframe engaging the lifting platform for driving the platform up and downbetween an upper and lower position, spaced upright posts in the pitbeneath the release track top, means for detachably securing the releasetrack top to the upper portions of the posts, supports fixed to the pitwall and slidably engaging the posts, an inwardly projecting lug fixedto the lower portion of each of the posts and a plurality of outwardlyprojecting stirrups fixed to the lifting platform and disposed forregistry beneath said lugs when the lifting platform is in its lowerposition below the release track top.

l. Apparatus for use in connection with a drop pit of the type having anelongated pit extending transversely benath a plurality of railroadtracks and bridged by a service track top and a release track topmovable vertically for use in servicing railway vehicle trucks and thelike comprising a drop table having a frame movable along rails on thebottom of the pit, a lifting platform on the frame, power means on thefram engaging the lifting platform for driving the platform up and downbetween an upper, an intermediate and a lower position, upright postsdisposed in the pit beneath the release track top and engageabletherewith for lifting the top, means for reciprocally supporting theposts, and members secured to the lifting platform for liftingengagement with said posts, said members being so disposed and arrangedas to prevent engagement with the posts except when the lifting platformis beneath the release track top and in its lower position.

5. Apparatus for use in connection with a drop pit of the type having anelongated pit extending transversely beneath a plurality of railwaytracks and bridged by a service track top and a release track topmovable vertically for use in servicing railway vehicle trucks and thelike comprising a drop table having a fram movable along rails on thebottom of the pit, a lifting platform on the frame, power means on theframe engaging the lifting platform for driving the platform up and downbetween an upper and lower position, a limit switch for stoppingdownward movement of the table, a lever on the lifting platform havingan arm in the path of the limit switch and movable from a first positionto a second position only by a, service track top on the platfrom,thereby positioning th platform in an intermediate position in theabsence of a service track top and in its lower position when theservice track top is carried by the platform, a plurality of uprightposts supported below the release track top for lifting engagementtherewith, each of said posts having an inwardly projecting lug near thelower end and a plurality of outwardly projecting stirrups fixed to thelifting platform for lifting engagement with the lugs only when theplatform is raised from said lower position beneath the release tracktop.

6. Apparatus for use in connection with a drop pit of the type having anelongated pit extending transversely beneath a plurality of railwaytracks and bridged by a service track top and a release track topmovable vertically for use in servicing railway vehicle trucks and thelike comprising a drop table having a frame movable along rails on thebottom of the pit, a lifting platform on the frame, power means on theframe engaging the lifting platform for driving the platform up and downbetween an upper and lower position, a plurality of upright supports inthe pit walls below the release track top, a post slidably mounted ineach of the supports, means for detachably fastening the release tracktop on the posts, an inwardly projecting lug fixed to the lower portionof each of the posts, outwardly projecting stirrups fixed to the liftingplatform and spaced for vertical registry with said lugs when theplatform is positioned below the release track top, a low limit switchon the frame and a lever mechanism on the platform for actuating thelimit switch and thereby restricting downward movement of the platformto an intermediate level or to said lower level of the platform, saidlevels being selected to dispose th stirrups above the lugs when theplatform is at its intermediate level and below the lugs when theplatform is at its lowest position, the lever mechanism being normallyin position to permit movement of the platform to said intermediateposition, said lever being moveable from such position by engagement ofa service track top only on the platform.

i. Apparatus for use in connection with a drop pit of the type having anelongated pit extending transversely beneath a plurality of railwaytracks and bridged by a service track top and a release track topmovable vertically for use in servicing railway vehicle trucks and thelike comprising a drop table having a frame movable along rails on thebottom of the pit, a lifting platform on the frame, power means on theframe and engaging the lifting platform for driving the platform up anddown between an upper and lower position, a plurailty of hollow uprightsupports in the pit walls below the release track top, a post slidablymounted in each of the supports, means for detachably fastening therelease track top on the posts, an inwardly projecting lug fixed to thelower portion of each of the posts, outwardly projecting stirrups fixedto the lifting platform and spaced for vertical registry with said lugswhen the platform is positioned below the release track top, a low limitswitch on the frame and a lever mechanism on the platform for actuatingthe limit switch and thereby restricting downward movement of theplatform at an intermediate level or at the lower level of saidplatform, said lever mechanism including a first arm pivotally securedto the platform and movable between two positions, both of saidpositions being in the path of the limit switch, and a second armconnected to the first arm and projecting upwardly beyond the surface ofthe platform for engagement with a service track top only carriedthereby.

8. Apparatus for use in connection with a drop pit of a type having anelongated pit extending transversely beneath a plurality of railwaytracks and bridged by a service track top and a release track topmoveable vertically for use in servicing railway vehicle trucks and thelike comprising a drop table having a frame moveable along railsextending along the bottom of the pit, a

lifting platform on the frame, power means on the frame engaging thelifting platform fordriving the platform up and down between an upperposition and a lower position, upright posts disposed in the pit beneaththe release track top for engagement therewith for lifting said top,means for reciprocally supporting the posts and interengageable means onthe lifting platform and on the posts for coupling the posts to theplatform as the platform is raised from its lower position beneath therelease track top.

9. Apparatus for use in connection with a drop pit of a type having anelongated pit extending transversely beneath a plurality of railwaytracks and bridged by a service track top and a release track topmoveable vertically for use in servicing railway vehicle trucks and thelike comprising a drop table having a frame moveable along railsextending along the bottom of the pit, a

lifting platform on the frame, power means for driving the platform upand down between an upper position and a lower position, upright postsdisposed in the pit beneath the release track top for engagementtherewith for lifting said top, means for reciprocally supporting theposts and interengageable means on the lifting platform and on the postsfor coupling the posts to the platform as the platform is raised fromits lower position beneath the release track top.

LOUIS D. HOLMES.

ROBERT S. HAMMOND.

References Cited in the file of this patent UNITED STATES-PATENTS Number

